You might try the Plex Preview channel which is up to 7.17.6 - I’ve been running Plex Preview for years pretty reliably and I feel like the most recent version sped up a bunch of the loading you’re describing. It at least felt snappier than usual since this latest version.
Plex for Roku - #398 by ljunkie - latest updates
Plex for Roku - #154 by ljunkie - how to get the Plex Preview channel.
I definitely notice my RokuTV experience is very slow but that’s because TCL put low-end chips in those while my older Roku box is very snappy and my older Roku stick falls somewhere in between but definitely faster than my RokuTVs.
On RokuTV, I turn off all the dynamic theme stuff - the color changing background to match images as that seems to help with the snappiness; at least it feels like it. I only have that enabled on my Roku Ultra box. That might help a bit to try if you have than dynamic background enabled.
You also might try unplugging from power for 30 seconds. Roku caches a LOT and the built in restart\reboot doesn’t clear those caches and pulling power can be the only way to fully clear it out. I’ve found when things get a little slow or buggy doing that can sometimes resolve some things - including asset loading issues.
